diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc992cc3c7b..65e7a44a74d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -588,6 +588,7 @@ Docs: https://docs.openclaw.ai
 - Network/runtime: avoid importing Undici's package dispatcher during no-proxy timeout bootstrap so external channel plugin fetch requests with explicit Content-Length keep working. Fixes #78007. Thanks @shakkernerd.
 - Status/doctor: treat a single healthy OpenClaw Gateway listener on loopback, LAN, or wildcard bind as the expected configured gateway instead of warning that the port is already in use. Fixes #77939. Thanks @GitHoubi and @brokemac79.
 - Agents/TTS: send media-bearing block replies directly when block streaming is off, so agent `tts` tool audio attached to a final text reply is delivered instead of being consumed before final Telegram/media delivery. Thanks @Conan-Scott.
+- Doctor: avoid crashing on partial Linux environments when the legacy crontab probe or terminal note wrapper receives missing or non-string output. Fixes #77773. Thanks @brokemac79 and @blackflame7983.
 - Gateway/performance: reuse the current compatible plugin metadata snapshot across hot read-only status, channel, auth, skills, and embedded agent settings paths, avoiding repeated synchronous plugin metadata scans during Gateway activity. Fixes #77983. Thanks @shakkernerd.
 - Tasks/maintenance: prune stale cron run session registry entries while preserving running cron jobs and non-cron sessions. Fixes #73867. Thanks @brokemac79.
 - Plugins: dispatch cached descriptor-backed tools by the resolved runtime tool name for unnamed factories, fixing multi-tool plugins whose shared manifest contracts exposed sibling tools but failed at execution. Fixes #78671. Thanks @zanni098.
diff --git a/src/commands/doctor-cron.test.ts b/src/commands/doctor-cron.test.ts
index 171372e4495..a96c9e8722a 100644
--- a/src/commands/doctor-cron.test.ts
+++ b/src/commands/doctor-cron.test.ts
@@ -422,4 +422,33 @@ describe("noteLegacyWhatsAppCrontabHealthCheck", () => {
 
     expect(noteMock).not.toHaveBeenCalled();
   });
+
+  it("ignores malformed crontab output instead of crashing", async () => {
+    await expect(
+      noteLegacyWhatsAppCrontabHealthCheck({
+        platform: "linux",
+        readCrontab: async () => ({
+          stdout: undefined,
+        }),
+      }),
+    ).resolves.toBeUndefined();
+    await expect(
+      noteLegacyWhatsAppCrontabHealthCheck({
+        platform: "linux",
+        readCrontab: async () => ({
+          stdout: 12345,
+        }),
+      }),
+    ).resolves.toBeUndefined();
+    await expect(
+      noteLegacyWhatsAppCrontabHealthCheck({
+        platform: "linux",
+        readCrontab: async () => ({
+          stdout: { lines: ["*/5 * * * * ~/.openclaw/bin/ensure-whatsapp.sh"] },
+        }),
+      }),
+    ).resolves.toBeUndefined();
+
+    expect(noteMock).not.toHaveBeenCalled();
+  });
 });
diff --git a/src/commands/doctor-cron.ts b/src/commands/doctor-cron.ts
index 0cda4155abf..a8258168b1e 100644
--- a/src/commands/doctor-cron.ts
+++ b/src/commands/doctor-cron.ts
@@ -22,7 +22,7 @@ type CronDoctorOutcome = {
   warnings: string[];
 };
 
-type CrontabReader = () => Promise<{ stdout: string; stderr?: string }>;
+type CrontabReader = () => Promise<{ stdout?: unknown; stderr?: unknown }>;
 
 const execFileAsync = promisify(execFile);
 const LEGACY_WHATSAPP_HEALTH_SCRIPT_RE =
@@ -153,8 +153,21 @@ async function readUserCrontab(): Promise<{ stdout: string; stderr?: string }> {
   };
 }
 
-function findLegacyWhatsAppHealthCrontabLines(crontab: string): string[] {
-  return crontab
+function coerceCrontabText(crontab: unknown): string {
+  if (typeof crontab === "string") {
+    return crontab;
+  }
+  if (crontab == null) {
+    return "";
+  }
+  if (typeof crontab === "number" || typeof crontab === "boolean" || typeof crontab === "bigint") {
+    return String(crontab);
+  }
+  return "";
+}
+
+function findLegacyWhatsAppHealthCrontabLines(crontab: unknown): string[] {
+  return coerceCrontabText(crontab)
     .split(/\r?\n/u)
     .map((line) => line.trim())
     .filter((line) => line.length > 0 && !line.startsWith("#"))
@@ -171,7 +184,7 @@ export async function noteLegacyWhatsAppCrontabHealthCheck(
     return;
   }
 
-  let crontab: string;
+  let crontab: unknown;
   try {
     crontab = (await (params.readCrontab ?? readUserCrontab)()).stdout;
   } catch {
diff --git a/src/terminal/note.ts b/src/terminal/note.ts
index 81d38fde18c..bb64ad3efb5 100644
--- a/src/terminal/note.ts
+++ b/src/terminal/note.ts
@@ -147,13 +147,30 @@ function wrapLine(line: string, maxWidth: number): string[] {
   return lines;
 }
 
+function coerceNoteMessage(message: unknown): string {
+  if (typeof message === "string") {
+    return message;
+  }
+  if (message == null) {
+    return "";
+  }
+  if (typeof message === "number" || typeof message === "boolean" || typeof message === "bigint") {
+    return String(message);
+  }
+  if (message instanceof Error) {
+    return message.message ? `${message.name}: ${message.message}` : message.name;
+  }
+  return "";
+}
+
 export function wrapNoteMessage(
-  message: string,
+  message: unknown,
   options: { maxWidth?: number; columns?: number } = {},
 ): string {
+  const text = coerceNoteMessage(message);
   const columns = options.columns ?? resolveNoteColumns(process.stdout.columns);
   const maxWidth = options.maxWidth ?? Math.max(40, Math.min(88, columns - 10));
-  return message
+  return text
     .split("\n")
     .flatMap((line) => wrapLine(line, maxWidth))
     .join("\n");
@@ -179,7 +196,7 @@ function createNoteOutput(columns: number): NodeJS.WriteStream {
   return output;
 }
 
-export function note(message: string, title?: string) {
+export function note(message: unknown, title?: string) {
   if (isSuppressedByEnv(process.env.OPENCLAW_SUPPRESS_NOTES)) {
     return;
   }
diff --git a/src/terminal/table.test.ts b/src/terminal/table.test.ts
index c61082a661c..dd28b82043b 100644
--- a/src/terminal/table.test.ts
+++ b/src/terminal/table.test.ts
@@ -24,7 +24,7 @@ describe("renderTable", () => {
     });
 
     expect(out).toContain("Dashboard");
-    expect(out).toMatch(/│ Dashboard\s+│/);
+    expect(out).toMatch(/[│|] Dashboard\s+[│|]/);
   });
 
   it("expands flex columns to fill available width", () => {
@@ -86,7 +86,7 @@ describe("renderTable", () => {
     const lines = out.split("\n").filter((line) => line.includes("a"));
     for (const line of lines) {
       const resetIndex = line.lastIndexOf(reset);
-      const lastSep = line.lastIndexOf("│");
+      const lastSep = Math.max(line.lastIndexOf("│"), line.lastIndexOf("|"));
       expect(resetIndex).toBeGreaterThan(-1);
       expect(lastSep).toBeGreaterThan(resetIndex);
     }
@@ -279,4 +279,12 @@ describe("wrapNoteMessage", () => {
     expect(resolveNoteColumns(79)).toBe(80);
     expect(resolveNoteColumns(120)).toBe(120);
   });
+
+  it("coerces nullish and non-string note messages before wrapping", () => {
+    expect(wrapNoteMessage(undefined, { maxWidth: 20, columns: 80 })).toBe("");
+    expect(wrapNoteMessage(null, { maxWidth: 20, columns: 80 })).toBe("");
+    expect(wrapNoteMessage(12345, { maxWidth: 20, columns: 80 })).toBe("12345");
+    expect(wrapNoteMessage(new Error("boom"), { maxWidth: 20, columns: 80 })).toBe("Error: boom");
+    expect(wrapNoteMessage({ message: "boom" }, { maxWidth: 20, columns: 80 })).toBe("");
+  });
 });